/********************************** (C) COPYRIGHT  *******************************
 * File Name          : ch32v30x_can.c
 * Author             : WCH
 * Version            : V1.0.0
 * Date               : 2021/06/06
 * Description        : This file provides all the CAN firmware functions.
 * Copyright (c) 2021 Nanjing Qinheng Microelectronics Co., Ltd.
 * SPDX-License-Identifier: Apache-2.0
 *******************************************************************************/
#include "ch32v30x_can.h"
#include "ch32v30x_rcc.h"

/* CAN CTLR Register bits */
#define CTLR_DBF            ((uint32_t)0x00010000)

/* CAN Mailbox Transmit Request */
#define TMIDxR_TXRQ         ((uint32_t)0x00000001)

/* CAN FCTLR Register bits */
#define FCTLR_FINIT         ((uint32_t)0x00000001)

/* Time out for INAK bit */
#define INAK_TIMEOUT        ((uint32_t)0x0000FFFF)
/* Time out for SLAK bit */
#define SLAK_TIMEOUT        ((uint32_t)0x0000FFFF)

/* Flags in TSTATR register */
#define CAN_FLAGS_TSTATR    ((uint32_t)0x08000000)
/* Flags in RFIFO1 register */
#define CAN_FLAGS_RFIFO1    ((uint32_t)0x04000000)
/* Flags in RFIFO0 register */
#define CAN_FLAGS_RFIFO0    ((uint32_t)0x02000000)
/* Flags in STATR register */
#define CAN_FLAGS_STATR     ((uint32_t)0x01000000)
/* Flags in ERRSR register */
#define CAN_FLAGS_ERRSR     ((uint32_t)0x00F00000)

/* Mailboxes definition */
#define CAN_TXMAILBOX_0     ((uint8_t)0x00)
#define CAN_TXMAILBOX_1     ((uint8_t)0x01)
#define CAN_TXMAILBOX_2     ((uint8_t)0x02)

#define CAN_MODE_MASK       ((uint32_t)0x00000003)

static ITStatus CheckITStatus(uint32_t CAN_Reg, uint32_t It_Bit);

/*********************************************************************
 * @fn      CAN_DeInit
 *
 * @brief   Deinitializes the CAN peripheral registers to their default reset
 *        values.
 *
 * @param   CANx - where x can be 1 or 2 to select the CAN peripheral.
 *
 * @return  none
 */
void CAN_DeInit(CAN_TypeDef *CANx)
{
	if (CANx == CAN1)
	{
		RCC_APB1PeriphResetCmd(RCC_APB1Periph_CAN1, ENABLE);
		RCC_APB1PeriphResetCmd(RCC_APB1Periph_CAN1, DISABLE);
	}
	else
	{
		RCC_APB1PeriphResetCmd(RCC_APB1Periph_CAN2, ENABLE);
		RCC_APB1PeriphResetCmd(RCC_APB1Periph_CAN2, DISABLE);
	}
}

/*********************************************************************
 * @fn      CAN_Init
 *
 * @brief   Initializes the CAN peripheral according to the specified
 *        parameters in the CAN_InitStruct.
 *
 * @param   CANx - where x can be 1 to select the CAN peripheral.
 *          CAN_InitStruct - pointer to a CAN_InitTypeDef structure that
 *        contains the configuration information for the CAN peripheral.
 *
 * @return  InitStatus - CAN InitStatus state.
 *             CAN_InitStatus_Failed.
 *             CAN_InitStatus_Success.
 */
uint8_t CAN_Init(CAN_TypeDef *CANx, CAN_InitTypeDef *CAN_InitStruct)
{
	uint8_t InitStatus = CAN_InitStatus_Failed;
	uint32_t wait_ack = 0x00000000;

	CANx->CTLR &= (~(uint32_t) CAN_CTLR_SLEEP);
	CANx->CTLR |= CAN_CTLR_INRQ;

	while(((CANx->STATR & CAN_STATR_INAK) != CAN_STATR_INAK) && (wait_ack != INAK_TIMEOUT))
	{
		wait_ack++;
	}

	if ((CANx->STATR & CAN_STATR_INAK) != CAN_STATR_INAK)
	{
		InitStatus = CAN_InitStatus_Failed;
	}
	else
	{
		if (CAN_InitStruct->CAN_TTCM == ENABLE)
		{
			CANx->CTLR |= CAN_CTLR_TTCM;
		}
		else
		{
			CANx->CTLR &= ~(uint32_t) CAN_CTLR_TTCM;
		}

		if (CAN_InitStruct->CAN_ABOM == ENABLE)
		{
			CANx->CTLR |= CAN_CTLR_ABOM;
		}
		else
		{
			CANx->CTLR &= ~(uint32_t) CAN_CTLR_ABOM;
		}

		if (CAN_InitStruct->CAN_AWUM == ENABLE)
		{
			CANx->CTLR |= CAN_CTLR_AWUM;
		}
		else
		{
			CANx->CTLR &= ~(uint32_t) CAN_CTLR_AWUM;
		}

		if (CAN_InitStruct->CAN_NART == ENABLE)
		{
			CANx->CTLR |= CAN_CTLR_NART;
		}
		else
		{
			CANx->CTLR &= ~(uint32_t) CAN_CTLR_NART;
		}

		if (CAN_InitStruct->CAN_RFLM == ENABLE)
		{
			CANx->CTLR |= CAN_CTLR_RFLM;
		}
		else
		{
			CANx->CTLR &= ~(uint32_t) CAN_CTLR_RFLM;
		}

		if (CAN_InitStruct->CAN_TXFP == ENABLE)
		{
			CANx->CTLR |= CAN_CTLR_TXFP;
		}
		else
		{
			CANx->CTLR &= ~(uint32_t) CAN_CTLR_TXFP;
		}

		CANx->BTIMR = (uint32_t) ((uint32_t) CAN_InitStruct->CAN_Mode << 30)
				| ((uint32_t) CAN_InitStruct->CAN_SJW << 24)
				| ((uint32_t) CAN_InitStruct->CAN_BS1 << 16)
				| ((uint32_t) CAN_InitStruct->CAN_BS2 << 20)
				| ((uint32_t) CAN_InitStruct->CAN_Prescaler - 1);
		CANx->CTLR &= ~(uint32_t) CAN_CTLR_INRQ;
		wait_ack = 0;

		while(((CANx->STATR & CAN_STATR_INAK) == CAN_STATR_INAK) && (wait_ack != INAK_TIMEOUT))
		{
			wait_ack++;
		}

		if ((CANx->STATR & CAN_STATR_INAK) == CAN_STATR_INAK)
		{
			InitStatus = CAN_InitStatus_Failed;
		}
		else
		{
			InitStatus = CAN_InitStatus_Success;
		}
	}

	return InitStatus;
}

/*********************************************************************
 * @fn      CAN_FilterInit
 *
 * @brief   Initializes the CAN peripheral according to the specified
 *        parameters in the CAN_FilterInitStruct.
 *
 * @param   CAN_FilterInitStruct - pointer to a CAN_FilterInitTypeDef
 *        structure that contains the configuration information.
 *
 * @return  none
 */
void CAN_FilterInit(CAN_FilterInitTypeDef *CAN_FilterInitStruct)
{
	uint32_t filter_number_bit_pos = 0;

	filter_number_bit_pos = ((uint32_t) 1)
			<< CAN_FilterInitStruct->CAN_FilterNumber;
	CAN1->FCTLR |= FCTLR_FINIT;
	CAN1->FWR &= ~(uint32_t) filter_number_bit_pos;

	if (CAN_FilterInitStruct->CAN_FilterScale == CAN_FilterScale_16bit)
	{
		CAN1->FSCFGR &= ~(uint32_t) filter_number_bit_pos;

		CAN1->sFilterRegister[CAN_FilterInitStruct->CAN_FilterNumber].FR1 =
				((0x0000FFFF
						& (uint32_t) CAN_FilterInitStruct->CAN_FilterMaskIdLow)
						<< 16)
						| (0x0000FFFF
								& (uint32_t) CAN_FilterInitStruct->CAN_FilterIdLow);

		CAN1->sFilterRegister[CAN_FilterInitStruct->CAN_FilterNumber].FR2 =
				((0x0000FFFF
						& (uint32_t) CAN_FilterInitStruct->CAN_FilterMaskIdHigh)
						<< 16)
						| (0x0000FFFF
								& (uint32_t) CAN_FilterInitStruct->CAN_FilterIdHigh);
	}

	if (CAN_FilterInitStruct->CAN_FilterScale == CAN_FilterScale_32bit)
	{
		CAN1->FSCFGR |= filter_number_bit_pos;

		CAN1->sFilterRegister[CAN_FilterInitStruct->CAN_FilterNumber].FR1 =
				((0x0000FFFF & (uint32_t) CAN_FilterInitStruct->CAN_FilterIdHigh)
						<< 16)
						| (0x0000FFFF
								& (uint32_t) CAN_FilterInitStruct->CAN_FilterIdLow);

		CAN1->sFilterRegister[CAN_FilterInitStruct->CAN_FilterNumber].FR2 =
				((0x0000FFFF
						& (uint32_t) CAN_FilterInitStruct->CAN_FilterMaskIdHigh)
						<< 16)
						| (0x0000FFFF
								& (uint32_t) CAN_FilterInitStruct->CAN_FilterMaskIdLow);
	}

	if (CAN_FilterInitStruct->CAN_FilterMode == CAN_FilterMode_IdMask)
	{
		CAN1->FMCFGR &= ~(uint32_t) filter_number_bit_pos;
	}
	else
	{
		CAN1->FMCFGR |= (uint32_t) filter_number_bit_pos;
	}

	if (CAN_FilterInitStruct->CAN_FilterFIFOAssignment == CAN_Filter_FIFO0)
	{
		CAN1->FAFIFOR &= ~(uint32_t) filter_number_bit_pos;
	}

	if (CAN_FilterInitStruct->CAN_FilterFIFOAssignment == CAN_Filter_FIFO1)
	{
		CAN1->FAFIFOR |= (uint32_t) filter_number_bit_pos;
	}

	if (CAN_FilterInitStruct->CAN_FilterActivation == ENABLE)
	{
		CAN1->FWR |= filter_number_bit_pos;
	}

	CAN1->FCTLR &= ~FCTLR_FINIT;
}

/*********************************************************************
 * @fn      CAN_StructInit
 *
 * @brief   Fills each CAN_InitStruct member with its default value.
 *
 * @param   CAN_InitStruct - pointer to a CAN_InitTypeDef structure which
 *        will be initialized.
 *
 * @return  none
 */
void CAN_StructInit(CAN_InitTypeDef *CAN_InitStruct)
{
	CAN_InitStruct->CAN_TTCM = DISABLE;
	CAN_InitStruct->CAN_ABOM = DISABLE;
	CAN_InitStruct->CAN_AWUM = DISABLE;
	CAN_InitStruct->CAN_NART = DISABLE;
	CAN_InitStruct->CAN_RFLM = DISABLE;
	CAN_InitStruct->CAN_TXFP = DISABLE;
	CAN_InitStruct->CAN_Mode = CAN_Mode_Normal;
	CAN_InitStruct->CAN_SJW = CAN_SJW_1tq;
	CAN_InitStruct->CAN_BS1 = CAN_BS1_4tq;
	CAN_InitStruct->CAN_BS2 = CAN_BS2_3tq;
	CAN_InitStruct->CAN_Prescaler = 1;
}

/*********************************************************************
 * @fn      CAN_SlaveStartBank
 *
 * @brief   This function applies only to CH32 Connectivity line devices.
 *
 * @param   CAN_BankNumber - Select the start slave bank filter from 1..27.
 *
 * @return  none
 */
void CAN_SlaveStartBank(uint8_t CAN_BankNumber)
{
	CAN1->FCTLR |= FCTLR_FINIT;
	CAN1->FCTLR &= (uint32_t) 0xFFFFC0F1;
	CAN1->FCTLR |= (uint32_t) (CAN_BankNumber) << 8;
	CAN1->FCTLR &= ~FCTLR_FINIT;
}

/*********************************************************************
 * @fn      CAN_DBGFreeze
 *
 * @brief   Enables or disables the DBG Freeze for CAN.
 *
 * @param   CANx - where x can be 1 to select the CAN peripheral.
 *          NewState - ENABLE or DISABLE.
 *
 * @return  none
 */
void CAN_DBGFreeze(CAN_TypeDef *CANx, FunctionalState NewState)
{
	if (NewState != DISABLE)
	{
		CANx->CTLR |= CTLR_DBF;
	}
	else
	{
		CANx->CTLR &= ~CTLR_DBF;
	}
}

/*********************************************************************
 * @fn      CAN_TTComModeCmd
 *
 * @brief   Enables or disabes the CAN Time TriggerOperation communication mode.
 *
 * @param   CANx - where x can be 1 to select the CAN peripheral.
 *          NewState - ENABLE or DISABLE.
 *
 * @return  none
 */
void CAN_TTComModeCmd(CAN_TypeDef *CANx, FunctionalState NewState)
{
	if (NewState != DISABLE)
	{
		CANx->CTLR |= CAN_CTLR_TTCM;

		CANx->sTxMailBox[0].TXMDTR |= ((uint32_t) CAN_TXMDT0R_TGT);
		CANx->sTxMailBox[1].TXMDTR |= ((uint32_t) CAN_TXMDT1R_TGT);
		CANx->sTxMailBox[2].TXMDTR |= ((uint32_t) CAN_TXMDT2R_TGT);
	}
	else
	{
		CANx->CTLR &= (uint32_t) (~(uint32_t) CAN_CTLR_TTCM);

		CANx->sTxMailBox[0].TXMDTR &= ((uint32_t) ~CAN_TXMDT0R_TGT);
		CANx->sTxMailBox[1].TXMDTR &= ((uint32_t) ~CAN_TXMDT1R_TGT);
		CANx->sTxMailBox[2].TXMDTR &= ((uint32_t) ~CAN_TXMDT2R_TGT);
	}
}

/*********************************************************************
 * @fn      CAN_Transmit
 *
 * @brief   Initiates the transmission of a message.
 *
 * @param   CANx - where x can be 1 to select the CAN peripheral.
 *          TxMessage - pointer to a structure which contains CAN Id, CAN
 *        DLC and CAN data.
 *
 * @return  transmit_mailbox - The number of the mailbox that is used for
 *        transmission or CAN_TxStatus_NoMailBox if there is no empty mailbox.
 */
uint8_t CAN_Transmit(CAN_TypeDef *CANx, CanTxMsg *TxMessage)
{
	uint8_t transmit_mailbox = 0;

	if ((CANx->TSTATR & CAN_TSTATR_TME0) == CAN_TSTATR_TME0)
	{
		transmit_mailbox = 0;
	}
	else if ((CANx->TSTATR & CAN_TSTATR_TME1) == CAN_TSTATR_TME1)
	{
		transmit_mailbox = 1;
	}
	else if ((CANx->TSTATR & CAN_TSTATR_TME2) == CAN_TSTATR_TME2)
	{
		transmit_mailbox = 2;
	}
	else
	{
		transmit_mailbox = CAN_TxStatus_NoMailBox;
	}

	if (transmit_mailbox != CAN_TxStatus_NoMailBox)
	{
		CANx->sTxMailBox[transmit_mailbox].TXMIR &= TMIDxR_TXRQ;
		if (TxMessage->IDE == CAN_Id_Standard)
		{
			CANx->sTxMailBox[transmit_mailbox].TXMIR |=
					((TxMessage->StdId << 21) | TxMessage->RTR);
		}
		else
		{
			CANx->sTxMailBox[transmit_mailbox].TXMIR |= ((TxMessage->ExtId << 3)
					| TxMessage->IDE | TxMessage->RTR);
		}

		TxMessage->DLC &= (uint8_t) 0x0000000F;
		CANx->sTxMailBox[transmit_mailbox].TXMDTR &= (uint32_t) 0xFFFFFFF0;
		CANx->sTxMailBox[transmit_mailbox].TXMDTR |= TxMessage->DLC;

		CANx->sTxMailBox[transmit_mailbox].TXMDLR =
				(((uint32_t) TxMessage->Data[3] << 24)
						| ((uint32_t) TxMessage->Data[2] << 16)
						| ((uint32_t) TxMessage->Data[1] << 8)
						| ((uint32_t) TxMessage->Data[0]));
		CANx->sTxMailBox[transmit_mailbox].TXMDHR =
				(((uint32_t) TxMessage->Data[7] << 24)
						| ((uint32_t) TxMessage->Data[6] << 16)
						| ((uint32_t) TxMessage->Data[5] << 8)
						| ((uint32_t) TxMessage->Data[4]));
		CANx->sTxMailBox[transmit_mailbox].TXMIR |= TMIDxR_TXRQ;
	}

	return transmit_mailbox;
}

/*********************************************************************
 * @fn      CAN_TransmitStatus
 *
 * @brief   Checks the transmission of a message.
 *
 * @param   CANx - where x can be 1 to select the CAN peripheral.
 *          TransmitMailbox - the number of the mailbox that is used for
 *        transmission.
 *
 * @return  state -
 *            CAN_TxStatus_Ok.
 *            CAN_TxStatus_Failed.
 */
uint8_t CAN_TransmitStatus(CAN_TypeDef *CANx, uint8_t TransmitMailbox)
{
	uint32_t state = 0;

	switch (TransmitMailbox)
	{
	case (CAN_TXMAILBOX_0):
		state = CANx->TSTATR
				& (CAN_TSTATR_RQCP0 | CAN_TSTATR_TXOK0 | CAN_TSTATR_TME0);
		break;

	case (CAN_TXMAILBOX_1):
		state = CANx->TSTATR
				& (CAN_TSTATR_RQCP1 | CAN_TSTATR_TXOK1 | CAN_TSTATR_TME1);
		break;

	case (CAN_TXMAILBOX_2):
		state = CANx->TSTATR
				& (CAN_TSTATR_RQCP2 | CAN_TSTATR_TXOK2 | CAN_TSTATR_TME2);
		break;

	default:
		state = CAN_TxStatus_Failed;
		break;
	}

	switch (state)
	{
	case (0x0):
		state = CAN_TxStatus_Pending;
		break;

	case (CAN_TSTATR_RQCP0 | CAN_TSTATR_TME0):
		state = CAN_TxStatus_Failed;
		break;

	case (CAN_TSTATR_RQCP1 | CAN_TSTATR_TME1):
		state = CAN_TxStatus_Failed;
		break;

	case (CAN_TSTATR_RQCP2 | CAN_TSTATR_TME2):
		state = CAN_TxStatus_Failed;
		break;

	case (CAN_TSTATR_RQCP0 | CAN_TSTATR_TXOK0 | CAN_TSTATR_TME0):
		state = CAN_TxStatus_Ok;
		break;

	case (CAN_TSTATR_RQCP1 | CAN_TSTATR_TXOK1 | CAN_TSTATR_TME1):
		state = CAN_TxStatus_Ok;
		break;

	case (CAN_TSTATR_RQCP2 | CAN_TSTATR_TXOK2 | CAN_TSTATR_TME2):
		state = CAN_TxStatus_Ok;
		break;

	default:
		state = CAN_TxStatus_Failed;
		break;
	}

	return (uint8_t) state;
}

/*********************************************************************
 * @fn      CAN_CancelTransmit
 *
 * @brief   Cancels a transmit request.
 *
 * @param   CANx - where x can be 1 to select the CAN peripheral.
 *          Mailbox -  Mailbox number.
 *            CAN_TXMAILBOX_0.
 *            CAN_TXMAILBOX_1.
 *            CAN_TXMAILBOX_2.
 *
 * @return  none
 */
void CAN_CancelTransmit(CAN_TypeDef *CANx, uint8_t Mailbox)
{
	switch (Mailbox)
	{
	case (CAN_TXMAILBOX_0):
		CANx->TSTATR |= CAN_TSTATR_ABRQ0;
		break;

	case (CAN_TXMAILBOX_1):
		CANx->TSTATR |= CAN_TSTATR_ABRQ1;
		break;

	case (CAN_TXMAILBOX_2):
		CANx->TSTATR |= CAN_TSTATR_ABRQ2;
		break;

	default:
		break;
	}
}

/*********************************************************************
 * @fn      CAN_Receive
 *
 * @brief   Receives a message.
 *
 * @param   CANx - where x can be 1 to select the CAN peripheral.
 *          FIFONumber - Receive FIFO number.
 *            CAN_FIFO0.
 *            CAN_FIFO1.
 *          RxMessage -  pointer to a structure receive message which contains
 *        CAN Id, CAN DLC, CAN datas and FMI number.
 *
 * @return  none
 */
void CAN_Receive(CAN_TypeDef *CANx, uint8_t FIFONumber, CanRxMsg *RxMessage)
{
	RxMessage->IDE = (uint8_t) 0x04 & CANx->sFIFOMailBox[FIFONumber].RXMIR;

	if (RxMessage->IDE == CAN_Id_Standard)
	{
		RxMessage->StdId = (uint32_t) 0x000007FF
				& (CANx->sFIFOMailBox[FIFONumber].RXMIR >> 21);
	}
	else
	{
		RxMessage->ExtId = (uint32_t) 0x1FFFFFFF
				& (CANx->sFIFOMailBox[FIFONumber].RXMIR >> 3);
	}

	RxMessage->RTR = (uint8_t) 0x02 & CANx->sFIFOMailBox[FIFONumber].RXMIR;
	RxMessage->DLC = (uint8_t) 0x0F & CANx->sFIFOMailBox[FIFONumber].RXMDTR;
	RxMessage->FMI = (uint8_t) 0xFF
			& (CANx->sFIFOMailBox[FIFONumber].RXMDTR >> 8);
	RxMessage->Data[0] = (uint8_t) 0xFF & CANx->sFIFOMailBox[FIFONumber].RXMDLR;
	RxMessage->Data[1] = (uint8_t) 0xFF
			& (CANx->sFIFOMailBox[FIFONumber].RXMDLR >> 8);
	RxMessage->Data[2] = (uint8_t) 0xFF
			& (CANx->sFIFOMailBox[FIFONumber].RXMDLR >> 16);
	RxMessage->Data[3] = (uint8_t) 0xFF
			& (CANx->sFIFOMailBox[FIFONumber].RXMDLR >> 24);
	RxMessage->Data[4] = (uint8_t) 0xFF & CANx->sFIFOMailBox[FIFONumber].RXMDHR;
	RxMessage->Data[5] = (uint8_t) 0xFF
			& (CANx->sFIFOMailBox[FIFONumber].RXMDHR >> 8);
	RxMessage->Data[6] = (uint8_t) 0xFF
			& (CANx->sFIFOMailBox[FIFONumber].RXMDHR >> 16);
	RxMessage->Data[7] = (uint8_t) 0xFF
			& (CANx->sFIFOMailBox[FIFONumber].RXMDHR >> 24);

	if (FIFONumber == CAN_FIFO0)
	{
		CANx->RFIFO0 |= CAN_RFIFO0_RFOM0;
	}
	else
	{
		CANx->RFIFO1 |= CAN_RFIFO1_RFOM1;
	}
}

/*********************************************************************
 * @fn      CAN_FIFORelease
 *
 * @brief   Releases the specified FIFO.
 *
 * @param   CANx - where x can be 1 to select the CAN peripheral.
 *          FIFONumber - Receive FIFO number.
 *            CAN_FIFO0.
 *            CAN_FIFO1.
 *
 * @return  none
 */
void CAN_FIFORelease(CAN_TypeDef *CANx, uint8_t FIFONumber)
{
	if (FIFONumber == CAN_FIFO0)
	{
		CANx->RFIFO0 |= CAN_RFIFO0_RFOM0;
	}
	else
	{
		CANx->RFIFO1 |= CAN_RFIFO1_RFOM1;
	}
}

/*********************************************************************
 * @fn      CAN_MessagePending
 *
 * @brief   Returns the number of pending messages.
 *
 * @param   CANx - where x can be 1 to select the CAN peripheral.
 *          FIFONumber - Receive FIFO number.
 *            CAN_FIFO0.
 *            CAN_FIFO1.
 *
 * @return  message_pending: which is the number of pending message.
 */
uint8_t CAN_MessagePending(CAN_TypeDef *CANx, uint8_t FIFONumber)
{
	uint8_t message_pending = 0;

	if (FIFONumber == CAN_FIFO0)
	{
		message_pending = (uint8_t) (CANx->RFIFO0 & (uint32_t) 0x03);
	}
	else if (FIFONumber == CAN_FIFO1)
	{
		message_pending = (uint8_t) (CANx->RFIFO1 & (uint32_t) 0x03);
	}
	else
	{
		message_pending = 0;
	}

	return message_pending;
}

/*********************************************************************
 * @fn      CAN_OperatingModeRequest
 *
 * @brief   Select the CAN Operation mode.
 *
 * @param   CANx - where x can be 1 to select the CAN peripheral.
 *          CAN_OperatingMode - CAN Operating Mode.
 *            CAN_OperatingMode_Initialization.
 *            CAN_OperatingMode_Normal.
 *            CAN_OperatingMode_Sleep.
 *
 * @return  status -
 *          CAN_ModeStatus_Failed - CAN failed entering the specific mode.
 *          CAN_ModeStatus_Success - CAN Succeed entering the specific mode.
 */
uint8_t CAN_OperatingModeRequest(CAN_TypeDef *CANx, uint8_t CAN_OperatingMode)
{
	uint8_t status = CAN_ModeStatus_Failed;
	uint32_t timeout = INAK_TIMEOUT;

	if (CAN_OperatingMode == CAN_OperatingMode_Initialization)
	{
		CANx->CTLR = (uint32_t) ((CANx->CTLR
				& (uint32_t) (~(uint32_t) CAN_CTLR_SLEEP)) | CAN_CTLR_INRQ);

		while(((CANx->STATR & CAN_MODE_MASK) != CAN_STATR_INAK) && (timeout != 0))
		{
			timeout--;
		}
		if ((CANx->STATR & CAN_MODE_MASK) != CAN_STATR_INAK)
		{
			status = CAN_ModeStatus_Failed;
		}
		else
		{
			status = CAN_ModeStatus_Success;
		}
	}
	else if (CAN_OperatingMode == CAN_OperatingMode_Normal)
	{
		CANx->CTLR &= (uint32_t) (~(CAN_CTLR_SLEEP | CAN_CTLR_INRQ));

		while(((CANx->STATR & CAN_MODE_MASK) != 0) && (timeout != 0))
		{
			timeout--;
		}
		if ((CANx->STATR & CAN_MODE_MASK) != 0)
		{
			status = CAN_ModeStatus_Failed;
		}
		else
		{
			status = CAN_ModeStatus_Success;
		}
	}
	else if (CAN_OperatingMode == CAN_OperatingMode_Sleep)
	{
		CANx->CTLR = (uint32_t) ((CANx->CTLR
				& (uint32_t) (~(uint32_t) CAN_CTLR_INRQ)) | CAN_CTLR_SLEEP);

		while(((CANx->STATR & CAN_MODE_MASK) != CAN_STATR_SLAK) && (timeout != 0))
		{
			timeout--;
		}
		if ((CANx->STATR & CAN_MODE_MASK) != CAN_STATR_SLAK)
		{
			status = CAN_ModeStatus_Failed;
		}
		else
		{
			status = CAN_ModeStatus_Success;
		}
	}
	else
	{
		status = CAN_ModeStatus_Failed;
	}

	return (uint8_t) status;
}

/*********************************************************************
 * @fn      CAN_Sleep
 *
 * @brief   Enters the low power mode.
 *
 * @param   CANx - where x can be 1 to select the CAN peripheral.
 *
 * @return  sleepstatus -
 *            CAN_Sleep_Ok.
 *            CAN_Sleep_Failed.
 */
uint8_t CAN_Sleep(CAN_TypeDef *CANx)
{
	uint8_t sleepstatus = CAN_Sleep_Failed;

	CANx->CTLR = (((CANx->CTLR) & (uint32_t) (~(uint32_t) CAN_CTLR_INRQ))
			| CAN_CTLR_SLEEP);

	if ((CANx->STATR & (CAN_STATR_SLAK | CAN_STATR_INAK)) == CAN_STATR_SLAK)
	{
		sleepstatus = CAN_Sleep_Ok;
	}

	return (uint8_t) sleepstatus;
}

/*********************************************************************
 * @fn      CAN_WakeUp
 *
 * @brief   Wakes the CAN up.
 *
 * @param   CANx - where x can be 1 to select the CAN peripheral.
 *
 * @return  wakeupstatus -
 *            CAN_WakeUp_Ok.
 *            CAN_WakeUp_Failed.
 */
uint8_t CAN_WakeUp(CAN_TypeDef *CANx)
{
	uint32_t wait_slak = SLAK_TIMEOUT;
	uint8_t wakeupstatus = CAN_WakeUp_Failed;

	CANx->CTLR &= ~(uint32_t) CAN_CTLR_SLEEP;

	while(((CANx->STATR & CAN_STATR_SLAK) == CAN_STATR_SLAK) && (wait_slak != 0x00))
	{
		wait_slak--;
	}
	if ((CANx->STATR & CAN_STATR_SLAK) != CAN_STATR_SLAK)
	{
		wakeupstatus = CAN_WakeUp_Ok;
	}

	return (uint8_t) wakeupstatus;
}

/*********************************************************************
 * @fn      CAN_GetLastErrorCode
 *
 * @brief   Returns the CANx's last error code (LEC).
 *
 * @param   CANx - where x can be 1 to select the CAN peripheral.
 *
 * @return  errorcode - specifies the Error code.
 *            CAN_ErrorCode_NoErr - No Error.
 *            CAN_ErrorCode_StuffErr - Stuff Error.
 *            CAN_ErrorCode_FormErr - Form Error.
 *            CAN_ErrorCode_ACKErr - Acknowledgment Error.
 *            CAN_ErrorCode_BitRecessiveErr - Bit Recessive Error.
 *            CAN_ErrorCode_BitDominantErr - Bit Dominant Error.
 *            CAN_ErrorCode_CRCErr - CRC Error.
 *            CAN_ErrorCode_SoftwareSetErr - Software Set Error.
 */
uint8_t CAN_GetLastErrorCode(CAN_TypeDef *CANx)
{
	uint8_t errorcode = 0;

	errorcode = (((uint8_t) CANx->ERRSR) & (uint8_t) CAN_ERRSR_LEC);

	return errorcode;
}

/*********************************************************************
 * @fn      CAN_GetReceiveErrorCounter
 *
 * @brief   Returns the CANx Receive Error Counter (REC).
 *
 * @param   CANx - where x can be 1 to select the CAN peripheral.
 *
 * @return  counter - CAN Receive Error Counter.
 */
uint8_t CAN_GetReceiveErrorCounter(CAN_TypeDef *CANx)
{
	uint8_t counter = 0;

	counter = (uint8_t) ((CANx->ERRSR & CAN_ERRSR_REC) >> 24);

	return counter;
}

/*********************************************************************
 * @fn      CAN_GetLSBTransmitErrorCounter
 *
 * @brief   Returns the LSB of the 9-bit CANx Transmit Error Counter(TEC).
 *
 * @param   CANx - where x can be 1 to select the CAN peripheral.
 *
 * @return  counter - LSB of the 9-bit CAN Transmit Error Counter.
 */
uint8_t CAN_GetLSBTransmitErrorCounter(CAN_TypeDef *CANx)
{
	uint8_t counter = 0;

	counter = (uint8_t) ((CANx->ERRSR & CAN_ERRSR_TEC) >> 16);

	return counter;
}

/*********************************************************************
 * @fn      CAN_ITConfig
 *
 * @brief   Enables or disables the specified CANx interrupts.
 *
 * @param   CANx - where x can be 1 to select the CAN peripheral.
 *          CAN_IT - specifies the CAN interrupt sources to be enabled or disabled.
 *            CAN_IT_TME.
 *            CAN_IT_FMP0.
 *            CAN_IT_FF0.
 *            CAN_IT_FOV0.
 *            CAN_IT_FMP1.
 *            CAN_IT_FF1.
 *            CAN_IT_FOV1.
 *            CAN_IT_EWG.
 *            CAN_IT_EPV.
 *            CAN_IT_LEC.
 *            CAN_IT_ERR.
 *            CAN_IT_WKU.
 *            CAN_IT_SLK.
 *          NewState - ENABLE or DISABLE.
 *
 * @return  counter - LSB of the 9-bit CAN Transmit Error Counter.
 */
void CAN_ITConfig(CAN_TypeDef *CANx, uint32_t CAN_IT, FunctionalState NewState)
{
	if (NewState != DISABLE)
	{
		CANx->INTENR |= CAN_IT;
	}
	else
	{
		CANx->INTENR &= ~CAN_IT;
	}
}

/*********************************************************************
 * @fn      CAN_GetFlagStatus
 *
 * @brief   Checks whether the specified CAN flag is set or not.
 *
 * @param   CANx - where x can be 1 to select the CAN peripheral.
 *          CAN_FLAG - specifies the flag to check.
 *            CAN_FLAG_EWG.
 *            CAN_FLAG_EPV.
 *            CAN_FLAG_BOF.
 *            CAN_FLAG_RQCP0.
 *            CAN_FLAG_RQCP1.
 *            CAN_FLAG_RQCP2.
 *            CAN_FLAG_FMP1.
 *            CAN_FLAG_FF1.
 *            CAN_FLAG_FOV1.
 *            CAN_FLAG_FMP0.
 *            CAN_FLAG_FF0.
 *            CAN_FLAG_FOV0.
 *            CAN_FLAG_WKU.
 *            CAN_FLAG_SLAK.
 *            CAN_FLAG_LEC.
 *          NewState - ENABLE or DISABLE.
 *
 * @return  FlagStatus - SET or RESET.
 */
FlagStatus CAN_GetFlagStatus(CAN_TypeDef *CANx, uint32_t CAN_FLAG)
{
	FlagStatus bitstatus = RESET;

	if ((CAN_FLAG & CAN_FLAGS_ERRSR) != (uint32_t) RESET)
	{
		if ((CANx->ERRSR & (CAN_FLAG & 0x000FFFFF)) != (uint32_t) RESET)
		{
			bitstatus = SET;
		}
		else
		{
			bitstatus = RESET;
		}
	}
	else if ((CAN_FLAG & CAN_FLAGS_STATR) != (uint32_t) RESET)
	{
		if ((CANx->STATR & (CAN_FLAG & 0x000FFFFF)) != (uint32_t) RESET)
		{
			bitstatus = SET;
		}
		else
		{
			bitstatus = RESET;
		}
	}
	else if ((CAN_FLAG & CAN_FLAGS_TSTATR) != (uint32_t) RESET)
	{
		if ((CANx->TSTATR & (CAN_FLAG & 0x000FFFFF)) != (uint32_t) RESET)
		{
			bitstatus = SET;
		}
		else
		{
			bitstatus = RESET;
		}
	}
	else if ((CAN_FLAG & CAN_FLAGS_RFIFO0) != (uint32_t) RESET)
	{
		if ((CANx->RFIFO0 & (CAN_FLAG & 0x000FFFFF)) != (uint32_t) RESET)
		{
			bitstatus = SET;
		}
		else
		{
			bitstatus = RESET;
		}
	}
	else
	{
		if ((uint32_t) (CANx->RFIFO1 & (CAN_FLAG & 0x000FFFFF))
				!= (uint32_t) RESET)
		{
			bitstatus = SET;
		}
		else
		{
			bitstatus = RESET;
		}
	}

	return bitstatus;
}

/*********************************************************************
 * @fn      CAN_ClearFlag
 *
 * @brief   Clears the CAN's pending flags.
 *
 * @param   CANx - where x can be 1 to select the CAN peripheral.
 *          CAN_FLAG - specifies the flag to clear.
 *            CAN_FLAG_RQCP0.
 *            CAN_FLAG_RQCP1.
 *            CAN_FLAG_RQCP2.
 *            CAN_FLAG_FF1.
 *            CAN_FLAG_FOV1.
 *            CAN_FLAG_FF0.
 *            CAN_FLAG_FOV0.
 *            CAN_FLAG_WKU.
 *            CAN_FLAG_SLAK.
 *            CAN_FLAG_LEC.
 *
 * @return  none
 */
void CAN_ClearFlag(CAN_TypeDef *CANx, uint32_t CAN_FLAG)
{
	uint32_t flagtmp = 0;

	if (CAN_FLAG == CAN_FLAG_LEC)
	{
		CANx->ERRSR = (uint32_t) RESET;
	}
	else
	{
		flagtmp = CAN_FLAG & 0x000FFFFF;

		if ((CAN_FLAG & CAN_FLAGS_RFIFO0) != (uint32_t) RESET)
		{
			CANx->RFIFO0 = (uint32_t) (flagtmp);
		}
		else if ((CAN_FLAG & CAN_FLAGS_RFIFO1) != (uint32_t) RESET)
		{
			CANx->RFIFO1 = (uint32_t) (flagtmp);
		}
		else if ((CAN_FLAG & CAN_FLAGS_TSTATR) != (uint32_t) RESET)
		{
			CANx->TSTATR = (uint32_t) (flagtmp);
		}
		else
		{
			CANx->STATR = (uint32_t) (flagtmp);
		}
	}
}

/*********************************************************************
 * @fn      CAN_GetITStatus
 *
 * @brief   Checks whether the specified CANx interrupt has occurred or not.
 *
 * @param   CANx - where x can be 1 to select the CAN peripheral.
 *          CAN_IT -  specifies the CAN interrupt source to check.
 *            CAN_IT_TME.
 *            CAN_IT_FMP0.
 *            CAN_IT_FF0.
 *            CAN_IT_FOV0.
 *            CAN_IT_FMP1.
 *            CAN_IT_FF1.
 *            CAN_IT_FOV1.
 *            CAN_IT_WKU.
 *            CAN_IT_SLK.
 *            CAN_IT_EWG.
 *            CAN_IT_EPV.
 *            CAN_IT_BOF.
 *            CAN_IT_LEC.
 *            CAN_IT_ERR.
 *
 * @return  ITStatus - SET or RESET.
 */
ITStatus CAN_GetITStatus(CAN_TypeDef *CANx, uint32_t CAN_IT)
{
	ITStatus itstatus = RESET;

	if ((CANx->INTENR & CAN_IT) != RESET)
	{
		switch (CAN_IT)
		{
		case CAN_IT_TME:
			itstatus = CheckITStatus(CANx->TSTATR,
					CAN_TSTATR_RQCP0 | CAN_TSTATR_RQCP1 | CAN_TSTATR_RQCP2);
			break;

		case CAN_IT_FMP0:
			itstatus = CheckITStatus(CANx->RFIFO0, CAN_RFIFO0_FMP0);
			break;

		case CAN_IT_FF0:
			itstatus = CheckITStatus(CANx->RFIFO0, CAN_RFIFO0_FULL0);
			break;

		case CAN_IT_FOV0:
			itstatus = CheckITStatus(CANx->RFIFO0, CAN_RFIFO0_FOVR0);
			break;

		case CAN_IT_FMP1:
			itstatus = CheckITStatus(CANx->RFIFO1, CAN_RFIFO1_FMP1);
			break;

		case CAN_IT_FF1:
			itstatus = CheckITStatus(CANx->RFIFO1, CAN_RFIFO1_FULL1);
			break;

		case CAN_IT_FOV1:
			itstatus = CheckITStatus(CANx->RFIFO1, CAN_RFIFO1_FOVR1);
			break;

		case CAN_IT_WKU:
			itstatus = CheckITStatus(CANx->STATR, CAN_STATR_WKUI);
			break;

		case CAN_IT_SLK:
			itstatus = CheckITStatus(CANx->STATR, CAN_STATR_SLAKI);
			break;

		case CAN_IT_EWG:
			itstatus = CheckITStatus(CANx->ERRSR, CAN_ERRSR_EWGF);
			break;

		case CAN_IT_EPV:
			itstatus = CheckITStatus(CANx->ERRSR, CAN_ERRSR_EPVF);
			break;

		case CAN_IT_BOF:
			itstatus = CheckITStatus(CANx->ERRSR, CAN_ERRSR_BOFF);
			break;

		case CAN_IT_LEC:
			itstatus = CheckITStatus(CANx->ERRSR, CAN_ERRSR_LEC);
			break;

		case CAN_IT_ERR:
			itstatus = CheckITStatus(CANx->STATR, CAN_STATR_ERRI);
			break;

		default:
			itstatus = RESET;
			break;
		}
	}
	else
	{
		itstatus = RESET;
	}

	return itstatus;
}

/*********************************************************************
 * @fn      CAN_ClearITPendingBit
 *
 * @brief   Clears the CANx's interrupt pending bits.
 *
 * @param   CANx - where x can be 1 to select the CAN peripheral.
 *          CAN_IT - specifies the interrupt pending bit to clear.
 *            CAN_IT_TME.
 *            CAN_IT_FF0.
 *            CAN_IT_FOV0.
 *            CAN_IT_FF1.
 *            CAN_IT_FOV1.
 *            CAN_IT_WKU.
 *            CAN_IT_SLK.
 *            CAN_IT_EWG.
 *            CAN_IT_EPV.
 *            CAN_IT_BOF.
 *            CAN_IT_LEC.
 *            CAN_IT_ERR.
 *
 * @return  none
 */
void CAN_ClearITPendingBit(CAN_TypeDef *CANx, uint32_t CAN_IT)
{
	switch (CAN_IT)
	{
	case CAN_IT_TME:
		CANx->TSTATR = CAN_TSTATR_RQCP0 | CAN_TSTATR_RQCP1 | CAN_TSTATR_RQCP2;
		break;

	case CAN_IT_FF0:
		CANx->RFIFO0 = CAN_RFIFO0_FULL0;
		break;

	case CAN_IT_FOV0:
		CANx->RFIFO0 = CAN_RFIFO0_FOVR0;
		break;

	case CAN_IT_FF1:
		CANx->RFIFO1 = CAN_RFIFO1_FULL1;
		break;

	case CAN_IT_FOV1:
		CANx->RFIFO1 = CAN_RFIFO1_FOVR1;
		break;

	case CAN_IT_WKU:
		CANx->STATR = CAN_STATR_WKUI;
		break;

	case CAN_IT_SLK:
		CANx->STATR = CAN_STATR_SLAKI;
		break;

	case CAN_IT_EWG:
		CANx->STATR = CAN_STATR_ERRI;
		break;

	case CAN_IT_EPV:
		CANx->STATR = CAN_STATR_ERRI;
		break;

	case CAN_IT_BOF:
		CANx->STATR = CAN_STATR_ERRI;
		break;

	case CAN_IT_LEC:
		CANx->ERRSR = RESET;
		CANx->STATR = CAN_STATR_ERRI;
		break;

	case CAN_IT_ERR:
		CANx->ERRSR = RESET;
		CANx->STATR = CAN_STATR_ERRI;
		break;

	default:
		break;
	}
}

/*********************************************************************
 * @fn      CheckITStatus
 *
 * @brief   Checks whether the CAN interrupt has occurred or not.
 *
 * @param   CAN_Reg - specifies the CAN interrupt register to check
 *          It_Bit - specifies the interrupt source bit to check.
 *
 * @return  ITStatus - SET or RESET.
 */
static ITStatus CheckITStatus(uint32_t CAN_Reg, uint32_t It_Bit)
{
	ITStatus pendingbitstatus = RESET;

	if ((CAN_Reg & It_Bit) != (uint32_t) RESET)
	{
		pendingbitstatus = SET;
	}
	else
	{
		pendingbitstatus = RESET;
	}

	return pendingbitstatus;
}
